Renesas ISL95816HRZ-T

Overview

ISL95816HRZ-T from Renesas (formerly Intersil) is a 4-phase VR12.5-compliant PWM controller IC for microprocessor core voltage regulation, featuring R3 modulator technology, 0.5% system accuracy over temperature, serial bus interface, and support for DCR/resistor current sensing. It enables adaptive multi-phase operation in notebook and desktop CPU power supplies.

For engineers reviewing the ISL95816HRZ-T datasheet, ISL95816HRZ-T pinout, ISL95816HRZ-T application, or ISL95816HRZ-T equivalent, key selection considerations include VR12.5 compliance, R3 modulator transient response, programmable slew rate and IMAX, remote differential voltage sensing, and phase-configurable operation (1–4 phases).

Technical Context

The ISL95816HRZ-T implements Intersil's Robust Ripple Regulator R3 Technology™, enabling variable switching frequency during load transients and automatic frequency scaling at light load to improve efficiency. It supports both lossless DCR current sensing with single NTC thermistor compensation and precision resistor-based sensing.

It communicates with the CPU via a serial control bus (SVID), provides programmable VBOOT startup voltage, adjustable overcurrent protection threshold, and adaptive body diode conduction time reduction. Load-line regulation is implemented per VR12.5 specification with differential remote sense inputs.

Key Specifications

Pinout & Package

ISL95816HRZ-T is housed in a 48-pin QFN package (7mm × 7mm, 0.5mm pitch) with exposed thermal pad. Pin functions are defined per Intersil FN7979 Rev 0.00.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multi-phase VR controller applications.

Compared with IR35201MTRPBF and RT8803AZSP, the ISL95816HRZ-T uniquely combines VR12.5 SVID 1.0 full compliance, R3 modulator transient speed, and 0.5% system accuracy - making it the only option qualified for Intel reference designs requiring PS4 state entry and sub-2µs load-step recovery.

Availability

ISL95816HRZ-T is available at Aetrix Electronics and suitable for notebook CPU VR, desktop high-performance VR, and VR12.5 server blade applications requiring stable component supply, long-term lifecycle support, and full Intel platform qualification.

Supply support for ISL95816HRZ-T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Renesas Electronics Corporation acquired Intersil in 2017 and continues to manufacture, test, and support its high-performance analog and power management portfolio.

The ISL95816HRZ-T belongs to Renesas' VR12.5-compliant CPU power controller product line, engineered specifically for Intel® client and mainstream server platforms requiring SVID interface, fast transient response, and high-voltage regulation accuracy.

FAQ

What is the primary function of the ISL95816HRZ-T in a CPU power delivery system?

The ISL95816HRZ-T serves as the main VR12.5-compliant PWM controller that regulates microprocessor core voltage using a 4-phase (configurable down to 1-phase) buck topology. It interprets SVID commands from the CPU, manages phase activation, implements R3 modulator control, and enforces safety limits. The ISL95816HRZ-T directly interfaces with external MOSFETs and current-sense elements to deliver tightly regulated Vcore with ±0.5% accuracy.

Does the ISL95816HRZ-T support both DCR and resistor-based current sensing?

Yes, the ISL95816HRZ-T supports dual current-sensing methods: lossless inductor DCR sensing with integrated NTC thermistor compensation for temperature drift correction, and precision resistor (shunt) sensing for higher accuracy where DCR variation is unacceptable. Both modes use differential inputs (IMONP/IMONN) and are selected via configuration pins. The ISL95816HRZ-T's design allows seamless migration between sensing topologies without changing the core control algorithm.

What is the significance of R3 Technology™ in the ISL95816HRZ-T?

R3 Technology™ is Intersil's proprietary ripple-based modulator architecture used in the ISL95816HRZ-T. It enables variable switching frequency during load transients, delivering faster response (<2µs) than fixed-frequency controllers, and automatically reduces frequency at light loads to improve efficiency. Unlike traditional voltage-mode or current-mode control, R3 eliminates need for external compensation components. The ISL95816HRZ-T leverages R3 to achieve both high dynamic performance and low quiescent power in a single IC.

Can the ISL95816HRZ-T be configured for fewer than four phases?

Yes, the ISL95816HRZ-T supports dynamic reconfiguration between 1-, 2-, 3-, and 4-phase operation via SVID commands from the CPU or platform firmware. Phase shedding is automatic during low-power states (e.g., PS4), reducing switching losses and improving light-load efficiency. The ISL95816HRZ-T retains full VR12.5 compliance and regulation accuracy in all configurations, with no hardware changes required - only SVID register writes determine active phase count.

What package type and thermal characteristics does the ISL95816HRZ-T use?

The ISL95816HRZ-T is packaged in a 48-pin QFN (7mm × 7mm, 0.5mm pitch) with an exposed thermal pad for enhanced heat dissipation. Its θJA is 32°C/W on a 4-layer JEDEC board, and junction-to-case (θJC) is 4.5°C/W. The package supports reflow soldering per IPC/JEDEC J-STD-020 and is RoHS-compliant. The ISL95816HRZ-T's thermal design enables operation up to +105°C ambient in high-density VRM layouts without forced airflow.